An intermittent signal that changes with temperature may be missed by a short test on a cold vehicle. The important evidence is the electrical behaviour when the symptom actually appears.

How to narrow it down

Document the warm-up stage, ambient conditions and whether the fault returns after cooling. Record the signal and its supplies together where practical. This helps distinguish a sensor or connection fault from a controller reacting correctly to a real change in the system.

What to include with the fault report

Include how long the vehicle runs before the fault and whether restarting changes it.

Do not use uncontrolled heating to provoke a fault. The test must respect the component, vehicle and instrument limits.

Speak to AXION

For complex vehicle-electronics diagnostics, send your vehicle details and fault report. Workshop assessment is in Didcot, Oxfordshire. Suitable postal or remote work is confirmed before booking.

Technical background from Pico Technology. The referenced design explains the principle; the vehicle-specific procedure determines the repair.